Duplex-cam motor



v 1927. 1.630 273 y H. A. NORDWICK DUPLEX CAM MOTOR Fi-led June 1'7,1926 3 Sheets-Sheet l INVENTOR HA .Nordwick May 1927' H. A. NORDWICKDUPLEX CAM MOTOR a Sheets-Sheet 2 Filed June 17. 1926 lllll INVENTORHA.N0rdwlZck H. A. NORDWICK DUPLEX CAM MOTOR May 31. 1927'. 1,630,273

Filed June 17. 1926 3 Sheets-Sheet 3 INVENTOR A. Nordwck BY Q gs AT/ORNYing a definite spacing from each other, could.

Patented May 31, 1921.

UNITED STATES HENRY A. NORDWICK, 011 s'rocxron, CALIFORNIA, nssxonon''10 DUPLEX Mouton PATENT orrlcn.

COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF DUPLEX-CAMMOTOR.

Application filed June 17, 1926. sci-m1 No. 116,558.

This invention relates to improvements in internal combustion enginesand particularly to that type using one or more large cams on a straightshaft, to take the place of the usual crank shaft. Q

Engines operating on this principle, but with different arrangement ofparts, are shown in Patent No. 1,528,164, dated March 3rd, 1925, to H.A. Nordwick; in the application of Messrs, Nordwick, Wickersham andMarchetti, Serial No. 736,889, filed September 10th, 1924; in theapplication of Nordwick and Marchetti Serial No. 3,252, filed Januar19th, 1925; and in the ap lication' of E. Wickersham, Serial lo. 35,330,filed June 6th, 1925.

The present invention represent-s an improvement over all the aboveidentified engines, as will be hereinafter evident.

In engines of this character some means must be provided for maintainingthe conand also to, prevent said rollers from jump ing from the cam atthe top of the stroke,

a tendency very evident at high eeds, when the momentum of the piston isgreat.

To insure proper operation of the engine and avoid a detrimentalhammering action and vibration, the contact of the rollers .with the cammust be positive at all points along the cam surface, as will beevident.

In the above mentioned previous devices, this problem was the main thingto be solved, and-various means were employed for effecting the desiredend.

In Patent No. 1,528,164, the solution took the form of opposed sets ofrollers on the connecting rods, which engaged differently alined faceson the cam structure. Since the distances between the two faces alongradial lines drawn through the cam-structure at diiferent points werenot of course the same, the rollers, being fixed and l1avnot of coursebear evenly against said faces at all times. They were either too far aart at times or too close at others, and t e result was that aconsiderable play of the connecting rods relative to the cam wasinevitably had.

The succeeding application showed a structure to accomplish the sameresult, using a series of fluid cylinders and a piston and leverarrangement to constantly bear.

down on the connectin rod rollers, and doing away with the dou le set ofrollers previously used.

This also was not a success, the give of the fluid, and the expense ofconstruction.

The subsequent applications made use of ear-connected equalizingstructures extendmg between connecting rods of adjacent cyl-.

inders, so that the upward movement of one rod would force the otherdown, and vice versa.

This arrangement, while theoretically good, failed to function properlyinpractice, due

to the fact that the metal in the equalizing arms and other parts had acertain springiness, which it was impossible to overcome without makingsaid parts so big and heavy as to be out of all proportion to the otherparts of the engine.f

The principal object of the present invention therefore is to-eliminateall theabove named defective features by roviding "an arrangement bmeans of whic 1 the "various connecting ro s will be positivelymaintained in unyielding relation to the cams at all points in theperiphery of the latter, and by designing the camwith which the rollersengage in such a manner as to enable the proper engagement of therollers with the cams to be had without any loose play or binding effectbeing had at any point.

A further object of the invention is to produce a simple and inexpensivedevice and These ob]ects I accomplish by means of.

such structure and relative arrangement of parts as will fully appear bya perusal of the following specification and claims.

on account of In the drawings similar characters of ref I erenceindicate corresponding parts. in the several views:

Fig. 1 is an end elevation mainly in section of my improved motor.

Fig. 2 is a fragmentary section on the hne 2-2 of Fig. 1, s owing thedouble cam and the connection of the rollers therewith.

Fig. 3 is a fragmentary longitudinal seccylindrical casing 1 having endplates 2 in cylinders 4 having pistons 5.

whichare journaled a shaft 3 concentric with. the casing.

,Mounted on and projecting outwardly from the casing rearwardly of theshaft are These cylindersare disposed 90 degrees apart. Connecting rods6 are pi'voted'in the various pistons and carry rollers 7 on their outerends which bear on cams 8 and 9 fixed in com mon in adjacentrelationship to each other on the shaft 3. The rollers 7 of adjacentcylinders are offset longitudinally suflicient so as to enable oneroller to ride on one cam and the other roller on the other cam.

Therollers of each adj acent pair of eylinders are permanently andrigidly connected together at their pivotal points by a right anglebellcrank or swing arm 10 which is mounted on a pivotal pin 11 supportedby a plate 12. This pin is disposed centrally of the length of the armsand is mounted centrally between the cylinder axes. Shims 13 are placedbetween the plate and the casing so that said plate and the pin mountedthereon may be moved closer to or drawn away from the shaft, as may benecessary to get the proper and exact engagement of the rollers with thecams.

In connecting the rollers with the connecting rods and arms 10 Ipreferably provide a sleeve 14 for each roller, extending beyondthesides thereof, andeither made as a separate piece or formed as one ofthe races of the roller, which is of the roller bearing type. Theconnecting rod 6oscillates on this sleeve. The arm structure 10 isformed as a pair of separated members straddling the end of the rod 6,and has central and cooperating bosses '15 projecting inwardly towardeach other and turnably mounted in the sleeve 14.

The bosses and arms are then secured togetherjby a screw bolt 16 or thelike. This arrangement holds the parts securely together and avoids theneed of using slit caps on the rods and arms. I

The cams are of that type having two high points A and two low points B,disposed in diametrally opposed relation to each other,,

and giving one revolution of the shaft for eaohfour strokes or onecomplete cycle of operations of the pistons, assuming that the motor isof the four cycle type.

The cam faces are generated throughout according to the swing oroscillation of the are reversed imposition relative to each other toobtain proper contact of the rollers therewith at all times. This doublecam and relative reversal of the positions thereof is necessary sinceone roller oscillates on an arc in a vertical plane toward the-shaft,while the other at the same time oscillates in a horizontal plane awayfrom the shaft. If the j axes of the rollers T bore directly against thecam the distance from the pin 11 to the cam at any point would always beconstant, regardless of the positioning of the cam relative to therollers and pin. The. added radius of the rollers however from thecenter thereof makes the distance from the pin 11 to the point ofcontact of the rollers with the cam different from the distance of saidpin to the point of contact of the other roller with said cam when therollers are at the top and bottom of their stroke. This difference isneutralized and reversed as the rollers reverse their position relativeto the high and low point of the camwith the rotation of the latter.This difference in distance must therefore be compensated for in thecan! design in order to insure the rollers riding properly thereon. Thisinherent difference "in distance also prohibits both rollers riding on asingle cam at all times, since otherwise the rollers being tied togetherwould at one time either bind on the cam or at another time would haveundue loose play thereon. I

Arbitrarily choosing and knowing the stroke of the piston, or thedistance from the low point B to the high point A the cam is thereforegenerated as follows:

The position of the pin is first arbitrarily determined, it beingassumed that said pin,is centralized on a line extending at 45 degreesfrom the shaft or midwaybetween the axial lines of adjacent cylinders,at the point of intersection of two right angle lines drawn tangent to acircle C representing .the center of stroke of the rollers. and so thatthe arcs D of oscillation of the rollers about the pin 11 will be thesame distance on one side of the respective vertical and horizontalcylinder axial lines E and F at the top and bot- 4 to bottom of thestroke. These circular lines are located by first considering themovement of the rollers to be uniformly accelerated and decelerated fromtop to bottom of the stroke. as is desired; the spacing of the circularlines being calculated as being in the proportion of 1, 3, 5, 5, 3, 1,relative to the degree radiating lines. That is, during thefifteeu'degrees of rotation of the cam the roller and piston travels oneunit, with the next 15 degrees of rotation. the roller travels threeunits, and so on.

Using the distance from the pin 11 to the center of the roller as aradius, arcs J are first described across the circular lines Hsuccessively from the outermost line inwardly, with the center as theintersection of the lines G with the circular line K, downwardly insuccessive order from the actual position of the pin 11, the arcs Jbeing located between the lines E and F. This line K is a lineconcentric with the shaft 3 passing through the axis of the pin 11.

Six of such arcs, counting from the pin 11 as a starting point, willrepresent a 90- degree movement of the cam or one stroke. Arcs L equalin radius to the radius of the roller are then described, toward theshaft, using the intersection of the lines H and the arcs J as thecenters. The cam outline R for said stroke is then projectedtangentially to the arcs 11 and represents the face of the cam engagedby the upper roller 7 on its down stroke and by the horizontal roller onits outward stroke. Arcs J, corresponding scribed across t e circularlines ,H successively between the lines E and F from the innermost lineoutwardly. The centers of these arcs are at the intersection of thelines G and K extending successively from the pin 11 as a starting pointupwardly.

oller-arcs are then described toward the shaft 3 with the intersectionof the arcs J with the lines H as centers. line S is then projectedtangentiallyto said arcs and represents the face of the cam engaged bythe horizontal roller/"7 on its downward stroke and engaged by the upperroller on its outward stroke. 4

As a result it will be found that the portion It is flatter than theportion S, the difference in distance between these two portions'corresponding'to the difference in distance between the pin 11 and thepoints of contact of the rollers with the cam at different times.

Having one 90 degree portion or one stroke of both cam faces generatedit is of course a mere matter of duplication to complete the lay-out ofthe cam. T0 attain the desired result the cams are made duplicates ofeach other with the faces of relatively flat outline disposed inalternately to the arcs J are then de- The cam outopposed order, and thecams are then placed together (or built as one) with such rela' tivelyfiat portions arranged in the reverse order, as shown in Fig. 1. This isnecessary, since as previously pointed out, the adjacent rollers aretiedtogether and must swing in opposite directions relative to the shaft asthey move in and out on their strokes. l

There being four strokes of each piston for each revolution of the shaftthe valve operating push rods 17 may of course operate on a cam 18mounted directly on the shaft 3, and in such a manner as to provide fora consecutive firing order of the cyliuders. Also the ignitiondistributor unit 19 may be mounted at one end of the shaft, so that themoving member of said unit-may be driven directly from the shaft. Thisavoids the necessity of, gears or a separate cam shaft for either thevalves 01' ignition mechanism.

The 90 degree radial type of engine above described is particularlysuitable for airplane use, four cylinders in two independent pairs beinggrouped in a common plane about the shaft 3.

In Fig. 4 I have shown a V type engine built on the same principle butmore suitable for motor vehicles.

In this engine the cylinders 4 are arranged in longitudinally spaced andalined pairs on the casing 1*, the cylinders of each pair being set 90degrees apart and symmetrically disposed relative to a vertical plane.The connecting rod rollers .7 of each pair are tied together as in theother type by a rigid arm structure 11 and bear as before on a double orduplex cam member 8 mounted on :the shaft 3.

The rollers of each additional pair of cylinders bear on individualcams, which are preferably set at an angle to the other cams, while allsaid cams are of course rigidly fixed on the one'central shaft.

From the foregoing description it will be readily seen that I haveproduced such a device assubstantially fulfills the objects of theinvention as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from suchdetail maybe resorted to as do not form a de arture from the spirit ofthe invention, as efined by the appended claims.

Havin thus described my invention what I c aim as new and useful anddesire to secure by Letters Patent is:

1. In an internal combustion engine, a shaft, a pair of cylindersdisposedradially of the shaft at an angle to each other, pistons in thecylinders, connecting rods pivoted in the pistons, rollers on the outerends of the rods, a cam structure on the shaft .the rollers.

on Which the rollers ride and desi ed to allow therollers to havefourstro es for each revolution of the shaft, and a rigid arm memberpivoted ina fixed position centrally of itslength between the cylindersand pivoted onto the rods in common with 2. Inan internal combustionengine, a shaft, a pair of cylinders disposed radially of the shaft at a90 degree angle to each other, pistons in the-cylinders, connecting rodspivoted in the pistons, rollers on the outer ends of therods, a rigidarm structure pivoted in a fixed position at the intersection of-linesprojected at right angles to the axial lines of the cylinders centrallyof the stroke of the rollers and connected at its ends to the rodsincommon with the r0llers,'and a cam structure on which the rollers beardesigned to allow :the rollers four strokes for each revolution of theshaft.

3;In an internal combustion engine, a shaft, a pair of cylindersdisposed radially of the shaft at a 90 degree angle to each other,pistons in the cylinders, connecting rods pivoted in the pistons,rollers on the outer ends of the rods, a rigid arm structure pivoted ina fixed position at the intersection of lines projected at right anglesto the axial lines of the cylinders centrally of the stroke of therollers and connected at its ends to therods in common with the rollers,whereby the rollers will oscillate simultaneously in right angled planesand in the reverse direction-to each other, and independent camsfor therollers each to allow of four strokes of the rollers for each revolutionof the shaft, the cams being each generated to compensate for therelative difference in movement of the other roller interconnectedtherewith to cause said rollers to'bear constantly against the cams atall points of their strokes.

4. In an internal combustion engine, a shaft, a pair of cylindersdisposed radially of the shaft at an angle to each other. pistons in thecylinders. connecting rods pivoted in the pistons, rollers on the outerends of the rods. means rigidly connecting said rollers together tocause them to oscillate radially of the shaft during their strokes inreverse directions, and a cam for each roller to allow of four strokesof'thc same with each revolution of the shaft. said cam being generatedwith respect to the movement ofthe other roller on its cam as to causesaid rollers to bear equally on their cams at any positions of the camsand rollers.

"5.'In an internal combustion engine, a shaft, a pair of cylindersdisposed radially of the shaft at a 90'degree angle to each other,pistons in the cylinders, connecting rods pivoted in the pistons,rollers on the outer ends of the rods. an arm structure pivoted. in afixed position at the intersection of lihes'projected at right angles tothe axial lines of the cylinders centrally of the stroke of the rollersand connected at its ends to the rods in common with the rollers,whereby the rollers will oscillate simultaneously in right angled planesand in the reverse direction to each other, and independent cams for therollers toallow of four strokes of the samewith each revolution of theshaft; a method of generating said cams to compensate for the relativedifference in movement of the rollers, consisting in describing a lineconcentric with the shaft and passing through the fixed pivot of the armstructure, laying off radial lines from the shaft to intersect saidcircular line, describing circular lines concentric with the shaftbetween the topand bottom positions of the axes of the rollers, theradial spacing of said circular lines being proportionate to the angularspacing of the radial lines,

intersecting said circular lines in order with arcs centered at theintersection of said radial lines with the first 'named circular line;in successive order and in both directions from said pivot, the arcscutting said circular lines on the opposite sides respectively of thepivot of the arm structure and in reverse order between the right angledaxial lines of the cylinders; the radius of said arcs being the distancebetween said pivot and the axes of the rollers, describing arcs towardone of said axial lines from the intersections of the first named arcswith the circular lines in successive order, the radius of said lastnamed arcs being the radius of the rollers. drawing lines tangentiallythrough said last named arcs in respective order, whereby the one-strokesur-- faces of the two cams are formed, and then laying out theremainder of the cams by placing said generated portions in alternatingand reverse order to each other abou the shaft as an axis. In testimonywhereof-VI aflix my signature.

HENRY A. NORDWICK.

